Acting Assistant Commissioner Brett McFadden told reporters the couple had been in a long-term relationship. However, this had broken down in recent years and Mr Edwards lived separately from the rest of the family at the Normanhurst address where he was discovered dead this morning.

Solicitor Olga Edwards arrived home on Thursday night to find her two teenage children had been killed.Source:Supplied

John Edwards, a financial planner from Sydney last night shot and killed his two teenage children before taking his own life. Picture: LinkedinSource:Supplied

Police say the 68-year-old went to the West Pennant Hills address yesterday, where the Ms Edwards and two children lived, to carry out the “targeted incident” related to domestic violence.

Police say there were custody hearings over the children during the past two years. Mr Edwards had a criminal record, however there were no apprehended violence orders in place at the time of the attack.

It is understood he was recently estranged from the children.

Police at the scene where a teenage girl and boy were shot in their bedrooms in a suburban home in West Pennant Hills. Picture: Dan Himbrechts.Source:AAP

The fatal shooting occurred at about 5.20pm on Thursday. Picture: David Swift.Source:News Corp Australia

A woman in her 30s arrived home to find police at her home and her two teenage children shot dead. Picture: Dan HimbrechtsSource:AAP

“We are aware of him, but he doesn’t have an extensive history and we don’t have any what we would call contemporary information in recent years,” Mr McFadden said. “I don’t believe (his criminal record) is extensive and, if it was, it was many years ago.

“The details about the nature of the relationship, particularly in recent times, and the level of access that the 68-year-old had to his children is subject to investigation.

“This was a planned activity on the part of the 68-year-old male and we are of the belief that shortly thereafter he has attended the address at Normanhurst and taken his own life.”

The father owned a number of firearms, including two powerful handguns legally registered in his name.

“We understand that those handguns came into his possession lawfully earlier this year,” Mr McFadden said.

He said the victims were found dead by officers called to the “horrific scene” following reports of gunshots.

“When you prepare yourself as a police officer, you prepare yourself to deal with the

most tragic of circumstances, but nothing can prepare you to walk into a home and see two children in that state,” he said.

“Not just police, but the ambulance officers responding as well. So, there is no words that we can say to the family. It is only our diligence in the investigation for the coroner that would satisfy their interest. Speaking with many last night, they had a role to play last night and they did it admirably.”

He added that he couldn’t “imagine the significant stress and heartache” the mother was going through.

“It was a very harrowing experience for the emergency services who responded,” he said.

“You’ve got a family that is going to struggle to come to terms with it and emergency responders will struggle to come to terms with what they have seen.”

Detectives are now on scene at the family’s home on Hull Rd, which remains a crime scene. It is understood the two teens’ bodies were removed just before 6am.

Forensic teams and homicide investigators had been searching the home all night for evidence, while Ms Edwards was recovering with friends after being treated for severe shock.

The murdered 15-year-old boy is understood to be a pupil at Pennant Hills High School. A spokesman for the school told news.com.au it had “no comment” on the death at this stage, as the victims are yet to be formally identified.

However, staff at the school are understood to be holding a meeting this morning to deal with the news.

Mr McFadden told news.com.au it had not yet been determined how many shots were fired but that police were speaking with several witnesses.

He told reporters the attack was a “very harrowing experience for those initial responding emergency service providers”.

He said paramedics, who were visibly shaken by what they had seen, were comforted by a NSW Ambulance chaplain.

“It is what can only be described as a tragic set of circumstances for the whole family,” he said.

About 150m of the road was blocked off, with witches hats stopping cars from entering one end, and uniformed police officers standing guard on both. Some residents who lived in the exclusion zone were escorted back inside their houses upon arriving late to the horror that, on this occasion, had come too close to home.

Mr Howard said he didn’t hear any gunshots. He was alerted to the incident when his daughter saw it on the news and contacted him before he came outside.

The home is still a crime scene. Picture: John GraingerSource:News Corp Australia

“I couldn’t believe it,” he said. “It’s so horrific … especially for such young people to be the ones killed.”

About 20 residents, including young children, gathered on the street while police examined the crime scene. Homicide detectives continued doorknocking neighbours late into the night in search of information as to exactly what transpired. For now, all that is certain, is that two young people who were alive in their homes just hours ago — are now dead.

To the West Pennant Hills Mother:

You are never alone. You are a woman, a mother, a survivor. A human of strength. And you are fragile. Surround yourself with friends and family that will hold you through this when you cannot imagine going on by yourself. You, are loved. 💕